Flow cytometry is an analytical technique used in a number of applications to measure physical and/or chemical properties of biological or nonbiological particles as they flow in a sample fluid, often an aqueous liquid medium, through an investigation cell (also referred to herein as a flow cell). Flow through the cell may be investigated by a variety of techniques, including subjecting the flow to electrical, acoustic and/or optical signals in measuring and analyzing responses to detect and evaluate particles in the sample.
When attempting to evaluate whether or not a particular particle is present in a sample fluid, one or more fluorescent stains or dyes may be added to the sample fluid. The dyes or stains are selected to fix on the particle of interest and to fluoresce when exposed to excitation light within a particular range of wavelengths. The fluorescent response light from the sample fluid may be detected by one or more photodetectors of the flow cytometry instrument, which in turn, generate one or more electrical signal data traces in which the voltage level at a particular instant in time indicates the level of fluorescent response light received by the detector from the sample fluid at that time. By identifying peaks in the signal data traces, an evaluation may be made regarding the presence of the target particle in the sample fluid. However, identifying valid signal peaks in signal data traces of a flow cytometer instrument can be challenging, particularly where two or more stains or dyes are used in the flow cytometry investigation which may result in cross-talk among signal data traces corresponding with a fluorescent response resulting from each stain or dye.